The present invention relates to data center infrastructure, and more particularly, this invention relates to providing dynamic latency-based calculations for links and paths through a network.
Institute of Electrical and Electronics Engineers (IEEE) publishes a multitude of standards, technical literature, and educational literature. IEEE 1588 provides for Precision Time Protocol (PTP) which is the facility of synchronizing clocks across a distributed Ethernet switching environment. After electing the master clock with the best stratum value (typically closer or closest to 1), the process of clock synchronization starts. As part of this process, transit delay is precisely calculated using a PTP delay request packet which is sent and received by a device. This transit delay is precisely equal to the latency of the path traversed by the PTP delay_request packet.
For various data center and telecom applications, using the lowest latency path may be important. Typically, each Ethernet switch in a network relies on a parameter referred to as a “path cost factor” which is configured, e.g., by one or more administrators of the network. In addition, all of the bridging and routing protocols use this path cost factor to find the shortest path or the most preferred path between any two devices in the network. Many if not most of the multipath algorithms also rely on this parameter.
However, even though the path cost factors are configured based on highest speed or available bandwidth of each of the Ethernet ports or paths in the network, the actual latency for any path through the network may vary dramatically. A standard 10 GbE port from one switch may provide a very different latency than a standard 10 GbE port of another switch. Thus, even an end-to-end latency of any of these paths through the network selected by a multipath algorithm may be very different, regardless of the path cost factor of those two paths being the same.
In order to provide a level of service and redundancy expected of modern networks to data packets, a highly available and lower latency path solution should be provided.